In the past, wireless communication networks have been generally used for only voice communications for mobile device users. However, the recent trend for these users of the mobile devices is to use the wireless communication networks not only for voice communications, but also for a variety of data communications. Thus, as a demand for faster data communications has significantly increased, wireless communication networks, such as WLAN or Bluetooth, are widely used for such data communications. However, due to their longer connection time and faster battery consumption, some mobile devices have been used to receive messages in the form of sound signals.
In conventional wireless communication networks using sound signals, a mobile device typically receives sound signals from a marker, which broadcasts messages in the form of sound signals to mobile devices located within a sound propagation range. In such broadcast mode, the marker is generally configured to broadcast messages to any devices within the local sound propagation area. As such, the communications between the marker and the mobile devices are typically unidirectional from the marker to the mobile devices. Further, since the marker broadcasts the sound signals to mobile devices in a localized region, it typically lacks the capability to transmit messages to specific mobile devices in a secure manner.
Thus, there is a need for a system and method that allows secure bi-directional communication of messages via a sound medium without requiring a lengthy connection time with mobile devices.